Emerald Ash Borer Update spring 2010

by Dave Scharfenberger, Board-Certified Master Arborist WI-0131B

Will emerald ash borer (EAB) be the end of unprotected ash trees in Wisconsin, the Midwest and the entire US? No one knows that answer but it could be, “Yes!” Locations of EAB have continued to increase in southeast Wisconsin. A common fact emerges when looking at other areas that are now dealing with fullblown infestations (Indiana, Ohio & Illinois): there is a significant increase in discoveries after the initial find. We are just beginning that period. This means continued bad news for ash trees, so we feel it is important to get updated on the latest information about EAB.

Where are we? EAB is very likely better established than we realize. Ash trees will continue to be at increasing risk.

What you should do? Evaluate your ash trees and decide if any are important enough (and healthy enough) to keep protected. Consider planting a different type of tree to replace your ash. Work with your Wachtel Tree Science Certified Arborist.

What are your options?

  • Treat to protect.
  • Plant a new tree nearby and remove the ash when infested.
  • Remove the ash now and replant now.
  • Do nothing, but be sure to monitor so the tree does not become a hazard. Dead trees are more expensive to remove.

How to protect?

  • Yearly, Imidacloprid soil systemic insecticide has a great track record and does not injure the tree.
  • Tree-Age trunk injections are proving to be a good choice but they do injure trees at injection sites. Protection with insecticides is great for key trees but it does mean continuing costs for future treatment.

What is new?

  • Some Imidacloprid products have a higher application rate for larger trees (important).
  • Tree-Age trunk injection protects for up to two years (maybe three).

When to start? Now! If you decide you want to protect your tree, it is important to start before it becomes infested. If you wait until after it is infested, control will be compromised. Planting a replacement tree now will get that new tree growing sooner.

Are there some good opportunities? Here is your chance to plant more variety into your landscape so future invasive insects or diseases do not impact you as hard.

Is there one perfect answer? No. Work with your Certified Arborist and your budget to determine what is best for you. What am I missing? Do not ignore important maintenance on key trees of other species. Remember that if your ash trees die, your remaining trees will be even more important to you! Keeping them healthy will be very important to your long-term landscape!

Whom to call? As always, work with your Wachtel Tree Science Certified Arborist.

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